1. Field of the Invention
The present invention generally relates to a sport boot, for gliding sport or any other sport requiring transmission of specific forces, which is more particularly adapted for skiing on snow, ice skating, or skating on solid ground using conventional roller skates or in-line roller skates.
2. Background and Material Information
For skating, whether on snow, ice or solid ground, the boot generally includes an external sole adapted to be affixed to the upper plate of a frame, on which the wheels are arranged, and from which an upper covering the foot extends in the direction of the skater's ankle.
The problems encountered with these boots adapted to the transmission of forces are due to the fact that they are generally designed according to the technique used for alpine ski boots, i.e., they have a monoblock shell made of a relatively rigid plastic material.
However, a degradation in the rigidity of the shell, caused by more or less high temperature, has been noted, especially in the application to boots for roller skating on solid ground, because this sport is mainly played in fine weather. This phenomenon is further accentuated in regions where temperatures are high.
This loss in the rigidity of the shell is an essential criterion for a good transmission of forces and good stability.
Of course, it would be possible to correct the aforementioned flaw by using materials whose bending modulus is higher, but it would be detrimental to the comfort and qualities for enveloping the foot.
A response to this problem is provided in certain boots by overmolding, in the base of the shell, a rigid insert which tends to compensate for the loss of rigidity caused in the latter by the aforementioned rise in the temperature.
This manufacturing method has proven expensive and not very reactive.